Synthesis, characterization, drug release and transdentinal delivery studies of magnetic nanocubes coated with biodegradable poly(2-(dimethyl amino)ethyl methacrylate)

Nanotechnology on magnetism and magnetic materials has been developed and studied extensively for the recent decades. Magnetic nanoparticles were applied in magnetic targeting, magnetic drug carriers, and diagnostic materials. In this work, the development of magnetic nanocomposites and their applications as drug carriers for dentistry were investigated. Well-defined ferromagnetic magnetite nanocubes (FMNCs) with the diameter of around 60 nm were synthesized using a thermal decomposition method at 290 °C with iron-oleate complexes as starting materials resulting in nanostructure with high saturation magnetization. The FMNCs were then coated with poly(2-(dimethyl amino)ethyl methacrylate) (PDMAEMA), a water-soluble, biodegradable, and pH-responsive polymer, in order to become good drug carriers with excellent dispersity in biological buffer, low cytotoxicity, and controllable drug release. The polymer coating was performed using atom transfer radical polymerization (ATRP). By using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, FMNCs/PDMAEMA showed the high compatibility in fibroblast and macrophage cell line with the cell viability of more than 80% after incubation with the highest nanocomposites concentration of 100 μg/mL for 24 h. Furthermore, the FMNCs/PDMAEMA subsequently demonstrated the anti-inflammatory effect on macrophages by suppression of pro-inflammatory cytokines, IL-6 and TNF-α production in a dose-dependent manner. The behavior of model drug alkaline hyperchlorite released from the FMNCs/PDMAEMA indicated that the drug release could be controlled by altering pH of the environment. As a result of successfully synthesized FMCNs/PDMAEMA, dentine infiltration of FMNCs/PDMAEMA was performed. It was observed that FMNCs/PDMAEMA could significantly infiltrate the dentine within 30 min under an external magnetic field. Our findings indicated the therapeutic potential of the FMNCs/PDMAEMA as transdentinal drug carriers with its high biocompatibility and anti-inflammatory property. - Highlights: • The uniform magnetite nanocubes coated with PDMAEMA was synthesized. • Cytotoxicity and immune response of nanocube-polymer composites were investigated. • Dentine infiltration of the composites was demonstrated as transdentinal delivery.